GREAT STEPS IN EVOLUTION 77 



labour and its structural aspect which we call 

 differentiation, the beginnings of sex and of 

 reproduction, the beginnings of a body and 

 of death. "Protozoology," as it is quaintly 

 called nowadays, is a fascinating study in 

 origins. 



THE PROTISTS. It is useful to retain 

 Haeckel's term "Protists" for those simplest 

 gf all ]iyjng-Creatu^gs r which lie at. the Wsf* of 

 the V-shaped tree of 



Has towards Distinctively planf. or 



i velv__animal characteristics . How far re- 

 moved even these simplest of the simple may 

 be from the first living creatures we do not 

 know, but they have remained, as it were, 

 in chronic indecision, neither clearly plants 

 nor animals. In studying them we are 

 brought face to face with one of the great 

 steps in evolution, and one of the earliest a 

 dichotomy, like many other great steps the 

 parting of the ways between plants and 

 animals. 



PLANTS AND ANIMALS. We have all grown 

 up with our minds coloured by the childish 

 game of '^Animal, ^Vegetable ojy Mineral ?" 

 and in too many schools they still teach that 



-But 



this. is a surviving error. of~4he alchemists*. 

 continued by the early encyclopaedists of 

 nature, but broken down by Linnaeus, who 



